Accumulated Other Comprehensive Income (Loss) - Schedule of Reclassifications (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	May 31, 2020	Feb. 29, 2020	Nov. 30, 2019	Aug. 31, 2019	May 31, 2019	Feb. 28, 2019	Nov. 30, 2018	Aug. 31, 2018	May 31, 2020	May 31, 2019	May 31, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense									$ 105,393	$ 101,736	$ 110,175
Tax expense									(181,931)	(219,764)	(57,069)
Amortization of interest rate locks, net of tax	$ 144,585	$ 234,520	$ 246,443	$ 250,812	$ 226,171	$ 200,923	$ 242,994	$ 212,547	876,360	882,635	$ 783,932
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax expense									(463)	(717)
Amortization of interest rate locks, net of tax									1,433	1,179
Interest Rate Contract | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense									$ 1,896	$ 1,896